Asolid, glowing-hot object will emit light over the full range of wavelengths resulting in a spectrum. if a diffuse and relatively cool cloud of gas is located between the glowing, hot object and an observer, the observer will detect an spectrum coming out of the cloud. another type of spectrum is given off by a neon sign which is a tube of gas whose electrons are excited by an electric current. the mostly red light given off by the sign is in the form of an spectrum.

Absorption Spectrum

Explanation:

The hot, dense source emits high energy photons of all wavelengths. Some of these photons are absorbed by electrons of cloud to excite them to a higher energy level which appear as dark lines in the spectra and we get Absorption Spectrum.

the word that best describes martin luther king jr.'s tone in the video is dignified

martin luther king, jr. was a social activist and baptist minister who played a key role in the american civil rights movement from the mid-1950s until his assassination in 1968. the video shows his manner and attitude having or showing a composed or serious manner that is worthy of respect so dignified is the correct answer

answerdmitry mendeleyev made a workable classification of the elements